Preparation of camphene



'Ratented Mar. 21, 1 2

v UNITED A STATES "PATENT orrlca.

THE ROESSLER &' HASSLACHER PORATION OF NEW YORK.

CHEMICAL C OMPAN Y OF NEW YORK, N. Y., A COB- rnnrAnA'rIon or cnmrnnn'n.

1% Drawing. Application filed February 26, 1927, Serial No. 171,373, and in Germany February 2'7, 192$.

' This invention refers to the preparation of camphene, which, as is well known, presents an important intermediate preparation of artificial cam hor from pin- .5, ene hydrochloride throu h esphtting out hydrogen chloride. v here are already-a -i-ininber. of methods which have been describ d for causing the necessary splitting out'o'f, hydrochloric acid, all of which, how- 10 ever, fretain more or less serious defects.

I have found, that the splitting out of hydrochloric acid proceeds in an exceptionally smooth imanner with the productionof practicallyquantitative yields of camphene 5 if the removaL of hydrochloric acid comes about through the action of alkali monoxide, as for example, .sollium monoxide. The ac- -tion of sodium monoxide on pinene hydrochloride proceeds withthe evolution of heat.- 20. Surprisingly however-5i no further reaction withthe hydrocarbon produced takes place in spite of the very great reactivity of sodium oxide, even when'a largegexcess of Na,() is used, for example up to '3 mols sodium monoxide for one inolof pin'enehydrochlor- E wample. v

A small quantity of inene hydrochloride and an excess of so 1ummonoxide are heated While excluded from moisture and in.

suitable contact, in an apparatus provided with a reflux condenser and stirrer. The

boiling point gradually period of 4 hours from at out 210 to 15 8 160 C. The heating under refluxis then continued for' another hour, whereu Jon the camphene formed distilled off either atmospheric or diminished pressure. The

40 mixture of sodium chloride and-sodium ox ide remaining behind in the reaction vessel phase in theoes'down over a can be utilized, for example, by working it up further into causticsoda'.

' B the rigorous excluslon of moisture and suitable arrangements for mixing the reactants, the above example can be carried out using only a small excess of sodium monoxide, especially if a 'lar e quantity of pinene hydrochloride is wor ed up at one time. The yields are excellent, well above 90%, the product is chlorine free and is separated from the residual sodium chloride and sodium monoxide by a simple distilla tion. In place of pinene hydrochloride its.

isomer bornyl chloride can be used with the same procedure and results, therefore in the appended claims I intend the term pinene consisting in refluxing pinene hydrochloride with an. excess of alkali metal monoxide until the boiling point of the reaction mixture indicatesthe completion of the reaction and then'distilling off the carnphene formed.

4.. The method of preparing cam hene consisting in refluxing pinene hydrochloride with an excess of sodium monoxide until the boiling point of the reaction mixture indicates the completion of the reaction and at then distilling off the camphene formed.

Signed at Frankfort-on-the-Main, Germany, this l2th day of Feby. A. D. 1927.

WILHELM SCHULENBURG.

'hydrochloride to include bornyl chloride. 

